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3-Valve Manifold
D/A Products Dial-A-Function Model Selector MM6UC Outline Drawing Dial-A-Function Design How to Order MM6UC Previous Dial-A-Function Model Next Dial-A-Function Model

  • Investment cast body with integral saddles for positive mounting to vertical or horizontal 2" pipe
  • Standard flanged instrument x flanged process connections - optional 1/2" FNPT process connections
  • PVC coated directional arrowhead handles with positive stops and integral PVC skirts which seal against the body to protect internal parts from contamination
  • Multi-purpose 1/4" Bleed Valve allows convenient depressurization of transmitter or checking for equalizer leakage while in service
  • Drain / Purge connections with 1/4" plugs
  • Bonnetless construction with unique tapered plug design
  • No metal to metal contact
  • Bubble tight seals
  • Adjustable packing nut stops interport and stem leakage
  • Zeroing function can be adapted to remote actuation
  • Integral Steam Heating system optional

The D/A MM6UC is a universal mounting 3-valve manifold that performs all the necessary functions of a 3-valve system by utilizing two 3-way valves working together instead of 3 independent 2-way valves. This sensible concept allows the operator to dial the desired function rather than manipulating a cluster of independent valves. The unique design of the UNIMOUNT properly groups and interlocks the porting to provide automatic fool-proof sequencing, drastically reducing the costly errors of improper operation inherent in 3-valve systems.

This same unique manifold excels in the ability to perform as both a manifold and a sturdy transmitter mount for systems that require remote mounting to a 2" pipe, direct mounting to the meter run flanges and direct mounting to an integral orifice block.

The Unimount design allows the completion of all piping prior to installation of the transmitter. The built in manifold mounting system permits easy removal of the transmitter without disturbing the process lines or mounting connections.

The D/A UNIMOUNT - A Truly Universal Instrument Adding an Extra Dimension of Simplicity, Convenience and Safety to Manifolding Practices.

Typical Installations

Direct Mounting to Meter Run Flanges

MM6UC Typical Installation
  • Allows mounting direct to the Meter Run Flanges for a practical closed coupled system
  • Eliminates the need for costly piping and fittings
  • Provides an extra stout and compact mounting system
  • Installation is simplified with D/A's unique AAF1 Adjustable Adapter Flanges which allow 1/4 turn adjustments when screwed into the meter run flanges providing a flush gasketed surface for mounting the UNIMOUNT. These AAF1 units utilize a simple side to side sliding adjustment form 1-15/16" to 2-1/4" to accomodate irregular dimensions between the meter run flanges.
  • When required, primary block valves which have 1/2" FNPT outlets can be installed at the meter run in front of the UNIMOUNT installation - we simply provide a longer support bracket.
  • The optional 1/2" FNPT rod-out connections with plugs provide a convenient system to rod-out directly into the meter run interior.

Direct Mounting to Integral Orifice Block

MM6UC Typical Installation
  • Provides a practical and compact mounting and manifolding system for integral orifice blocks
  • Locates the transmitter up and out of the meter run for ease of servicing
  • If desired, the UNIMOUNT can be mounted to a 2" pipe for an extra sturdy support
  • With the rod-out option, the integral orifice block porting can be conveniently serviced

Remote Mounting to a 2" Pipe

MM6UC Typical Installation
  • Allows completion of all piping, construction and pressure testing without the transmitter
  • Provides convenient and easy removal of the transmitter without disturbing the process lines, connections or mounting for a safe and sensible installation.
  • Eliminates undue strain and fatigue on all connections and components by locating the transmitter center of gravity directly above the 2" pipe.
  • Flanged process connections provide universal versatility by:
    1. Converting directly to 1/2" tube fittings with D/A's AFT4 Adapter Flanges
    2. Converting directly to socket weld connections with D/A's AFSW4 Adapter Flanges
    3. Converting directly to 1/2" FNPT with D/A's AFF4 Adapter Flanges or utilizing the transmitter 2-bolt oval flanges
Normal Mode
MM6UC Normal Mode

Zeroing Mode
MM6UC Zeroing Mode

Depressurization Mode
MM6UC Depressurization Mode

Isolation Mode
MM6UC Isolation Mode

Equalizer Leakage
MM6UC Equalizer Leakage Mode
Normal Mode
With both valve handles in the normal position, the MM6UC is in the normal mode with both process inlets open and the equalizing port blocked.
Zeroing Mode
By dialing the Zeroing Valve handle to the ZERO position, the MM6UC is automatically switched to the zeroing mode which completely and properly prepares the transmitter for zeroing by (1)first blocking one inlet impulse line and (2) then opening the equalizing port which bypasses the blocked inlet to equalize the P cell at process pressure. Because it basically operates like a 3-way valve, this forced zeroing sequence provides fool-proof operation and safety. After correcting for zero offset, the transmitter is returned to service by simply redialing the handle to the NORMAL position which, again, correctly sequences back to the service mode by closing the equalizer first and then reopening the blocked inlet.
Depressurization Mode
The first step in depressurizing a transmitter is to equalize the H.P. and L.P. sides to avoid possible damage to the transmitter. This is done by dialing the Zeroing Valve to the ZERO position. Next, the Blocking Valve can be dialed to the DEPRESS position which blocks off the process pressure allowing both cavities of the transmitter to be simultaneously depressurized thru the common vent valve.
Isolation Mode
By dialing the Zeroing Valve and Blocking Valve handles to the ZERO and BLOCKED positions respectively, the MM6UC is automatically switched to the islolation mode where both inlets are blocked and the equalizing port is closed. The transmitter is now safely isolated and prepared for field servicing, recalibration or removal. The transmitter is returned to service by simply redialing the handles to their NORMAL positions which, again, correctly sequences back to the service mode by leaving the equalizer blocked and reopening both inlets.
Testing for Equalizer Leakage
Equalizer leakage can be checked by leaving the Zeroing Valve in the NORMAL position and dialing the Blocking Valve to the BLOCKED position. In this mode, the equalizers on the 3-way Zeroing Valve and 3-way Blocking Valve are both closed. The cavity between these blocked equalizers can now be vented to check for leakage. If leakage is detected, slightly tighten the Zeroing Valve packing nut.

Note: Because of the unique fool-proof design, the Zeroing Valve and Blocking Valve handles can be dialed to their respective positions in any order without causing improper operation.
Max Ratings:
  6000psi @ -150ºF to 150ºF
  2500psi @ 220ºF
 Flanged instrument x Flanged process
Design Codes:

ANSI B31.1, B16.5, NACE MR-01-75(special order)
Material Codes:
Barstock, A479 - 316, A276-316;
Cast, ASTM-A743 CF3M, ASTM-A-351 CF3M, A 276-316.
Materials of Construction:
 Body: Investment cast 316SS or low grade (non-certified) SS
 Wetted Plug: 316SS
 Plug Liner: Teflon or Glass Filled Teflon
 Face Seals: Ryton reinforced Teflon
 Non-Wetted Trim: 303SS
 Handle: Cast aluminum arrowhead - PVC coated
 Plugs / Bleed Valve:303SS

Exotic materials: Hastelloy C, Monel, Alloy 20, etc. consult factory.
All units are supplied with 4 transmitter mounting bolts, 2 face seals and 2 U-bolts.
Assurance of Satisfaction: When properly installed, D/A guarantees the MM6UC to be free from defective workmanship and material under normal use and service for a period of one year from date of shipment.

Code  Dial-A-Function, Unimount 3-valve manifold
MM6UC  Flanged (instrument) x Flanged (process)
| Code   Plug Liner
| T  Teflon
| FT  Glass Filled Teflon
| | Code  Body
| | S  Stainless Steel, 316
| | C  Nickel Plated C.S.
| | | Code  Wetted Plug
| | | S  Stainless Steel, 316
| | | | Code  Options
| | | | ALH  Arrowhead Locking Handles
| | | | F4  1/2" FNPT Process Connections
| | | | IP  Interlock Protection
| | | | RO  Rod-Out connections
| | | | SH  Integral Steam Heating System
| | | | MRML  **Meter Run Mounting Kit for liquid service
| | | | MRMV  **Meter Run Mounting Kit for vapor service
| | | | |  
Model Number

**Note: If primary block valves will be installed at the meter run flanges, add a "B" to the options (MRMLB or MRMVB) and a longer support bracket will be included.


D/A Manufacturing Co., Inc.
Hwy 86 East or P.O. Box T
Tulia, TX  79088-0920 USA
Phone: (806)995-2316
FAX: (806)995-4601